The present invention relates to a vehicle-mounted network system and, more specifically, to a system that provides means for gathering data from an ECU (electronic control unit) in a diagnostic equipment.
A vehicle system is of an autonomous decentralized type in which an ECU coupled to a vehicle network broadcasts information needed for any other ECUs, and operates to capture any information needed for its own. Information technology (IT) has been progressing to the field of vehicles, e.g., a large number of ECUs achieve their cooperative control through exchange of vehicle control information over a vehicle network. With the improvement of performance in the vehicles, the number of the ECUs for mounting to the vehicles is increased, and thus data flowing over the network is also increased in amount. The concern here is that the vehicle network generally used, i.e., CAN (Control Area Network), has a limitation of the number of units for coupling thereto, and with the increase of the number of the ECUs as such for mounting to the vehicles, the network resultantly becomes complicated in configuration. This thus results in a difficulty in isolating problems and specifying the cause of a defect, if occurred.
In consideration of such background circumstances, a data recorder for gathering and recording the vehicle control information flowing over the vehicle network is considered useful. With such a data recorder, the gathered vehicle control information is used for defect analysis.